Flow control for ventilating hood

ABSTRACT

A VENTILATING KITCHEN HOOD INCLUDING A CASING IN THE FORM OF A RECTANGULAR POLYHEDRON WITH A SHORT WIDE FRONT OPENING AND HAVING A DRAWER SLIDABLE THROUGH THE FRONT OPENING. THE DRAWER HAS AN INTAKE PORT EXTENDING ACROSS A PORTION OF THE BOTTOM PANEL AND INCLUDES   DUCT STRUCTURE HAVING AN AIR FILTER THEREIN. A FAN MOUNTED WITHIN THE CASING DRAWS AIR INTO THE DRAWER, THROUGH THE AIR FILTER AND OUT OF THE CASING.

Nov. 9, 1971 J. E. STALKER FLOW CONTROL FOR VENTILATING HOOD 3Sheets-Sheet 1 Original Filed Jan. 21, 1965 FIG.!

FIG.4

FIG.3

INVENTOR JAMES E. STALKER ATTORNEY Nov. 9, 1971 J. E. STALKER FLOWCONTROL FOR VENTILATIHG HOOD Original Filed Jan. 21, 1965 3 Sheets-Sheet2 NVENTOR JAMES E. sm. KER

A A. @4 wt ATTORNEY NOV. 9, 1971 5. STALKER Re. 27,225

FLOW CONTROL FOR VENTILA'I'ING HOOD Original Filed Jan. 21, 1965 3Sheets-Sheet 5 FIG. 7

INVENTOR JAMES E. STALKER ATTORNEY United States Patent 27,225 FLOWCONTROL FOR VENTILATING HOOD James E. Stalker, Dallas County, Tex.,assignor to Home Metal Products Company, Plano, Tex.

Original No. 3,387,431, dated June 11, 1968, Ser. No. 426,782, Jan. 21,1965. Application for reissue May 26, 1969, Ser. No. 835,287 The portionof the term of the patent subsequent to May 3, 1983, has been disclaimedInt. Cl. B01d 46/00 US. Cl. 55-470 19 Claims Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE A ventilating kitchen hood including a casingin the form of a rectangular polyhedron with a short wide front openingand having a drawer slidable through the front opening. The drawer hasan intake port extending across a portion of the bottom panel andincludes duct structure having an air filter therein. A fan mountedwithin the casing draws air into the drawer, through the air filter andout of the casing.

This invention relates to a ventilating hood of the type employed fortreating fumes and vapors over food preparation areas, and moreparticularly to the control of air flow through filtartion elements.

In a more specific aspect, the invention relates to pull-out typeventilating hoods for kitchens.

There has developed a demand for ventilating kitchen hoods whichminimize the space required therefor and which, at the same time, willprovide an adequate flow of air so that undesirable vapors and entrainedgrease and the like may be removed from the air above a food preparationarea. By the present invention, a system is provided which occupies aminimum of space, which may be retracted when not in use, and whichprovides specifically for the control of air flow through filters andover the motor driving the fan.

In accordance with the invention, a kitchen filter is provided which hasa casing in the form of a rectangular polyhedron with a short wide frontopening. A drawer is slidable through the front opening and has anintake port extending across the front half of a bottom panel. A fan ismounted within the casing adjacent to a rear panel for drawing air intothe drawer through the intake port. Duct structure directs air flow fromthe fan out of the casing. An air filter is positioned in a planeparallel to the intake port and in the air path leading to the fan. Asecondary duct structure preferably is provided for directing airthrough the motor and into the air stream propelled by the fan.

In one form the filter is a ductless unit. The drawer has a centralmotor and two squirrel-cage fan elements mounted therein adjacent to arear panel for drawing air into the drawer through the intake port. Ductstructure in the drawer includes chambers for the fan elements open atopposite ends and an output channel for directing air flow from the fanout of the drawer at the front half of a top panel. The air filter islocated between the inlet port and the fan and is thus in the path ofair flow. In this embodiment, structure preferably is provided forpreferentially directing air through the motor into only one of thechambers.

In another form, the filter may be connected to an exhaust duct, inwhich case, the fan elements and the driving motor are mounted in therear of the casing in which the drawer operates. The drawer and thecasing form a duct structure for control of air flow into the drawer andout at the top of the casing. Controlled flow of air is maintained overthe motor from a separate intake port.

For a more complete understanding of the present invention and forfurther objects and advantages thereof, reference may now be had to thefollowing description taken in conjunction with the accompanyingdrawings in which:

FIGURE 1 is a top view, partially broken away, of a drawer-type hood inwhich the driving fan is mounted in the drawer;

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1;

FIGURE 3 is a sectional view taken along line 33 of FIGURE 1;

FIGURE 4 is a sectional view taken along line 44 of FIGURE 1;

FIGURE 5 is a partial sectional view showing the mounting for thedrawer;

FIGURE 6 is an exploded view of a second embodiment of the invention inwhich the fan is mounted on the casing rather than in the drawer; and

FIGURE 7 illustrates a hood having flow protective action for the fanmotor.

Referring now to FIGURE 1, a pull out hood is shown. A relativelyshallow casing 10 serves as a receptacle into which a drawer 11 may beinserted. The casing 10 has sides 12 and 13, a bottom panel 14, a toppanel 15 and a back panel 16. The top panel 15 is shown broken away sothat the interior of the casing may be seen. All of the panels exceptthe bottom panel 14 are continuous and are made of suitable sheet metal.However, the bottom panel 14 is provided with a screened aperture 18near the rear center portion thereof.

As best seen in FIGURE 5, the bottom panel 14 and the top panel 15 arecoupled together by the side panel 12 which is formed to overlap themargins of panels 14 and 15. An inner plate 20 is fitted into the unit10 on the left side and supports two pairs of rollers. As seen in FIGURE1, rollers 21 and 22 are mounted near the upper margin of the plate 20.As seen in FIGURE 5, roller 22 and roller 23 engage top and bottomgrooves extending along the side plate 24 of the drawer unit 11. Theplate 20 is broken at right angles near the upper and lower edgesthereof to engage the inner surface of the bottom plate 14 and the topplate 15. The bracket 20, plates 12, 14 and 15 may then be securedtogether, as by welding or riveting, through the flanges 25 and 26,respectively. The end plate 24 of the drawer 11 is suitably formed toprovide ways in which the rollers 21-23 opcrate.

Referring again to FIGURE 1, the filter drawer 11 is supported by therollers, as above described, by insert 20 and a companion insert 27 onthe right hand side. Drawer 11 may be opened to extend from the casing10 or may be retracted or closed into the casing 10 as required.

In the embodiment illustrated in FIGURE 1, a twin squirrel-cage fan unit30 is mounted at the rear of the drawer 11 and comprises a shroudedmotor 31 and a pair of squirrel-cage fan elements 32 and 33. As bestseen in FIGURE 2, the bottom panel 40 of the drawer 11 has an elongatedrectangular opening 35 near the front margin thereof. A pair of filterelements 36 and 37 are supported in suitable mounting brackets in theopening 35. The upper plate 38, the back plate 39 and the partial bottomplate 40 form an enclosure into which the air is drawn through thefilter elements 36 and 37, as indicated by arrow 42. The air may thentravel rearwardly from the location of the filter elements 36 and 37.The air path is illustrated by the dotted and solid portions of thearrow 42. After leaving the fan 32, the air passes outwardly through anoutput duct 41 which opens onto the upper front surface of the drawer.

The side of the duct 41 is shown in FIGURE 2. The mouth of the duct 41may be seen in FIGURE 1. Since the fan unit 30 is mounted at the rear ofthe drawer 11, the intake air travels through the filters 36 and 37rearwardly into the ends of the fan elements 32 and 33 and then upwardand forward through the duct 41. When the drawer is open, the rear edge43 of the mouth of the output duct 41 is located slightly rearward ofthe front edge of the casing 10. The filter 36 is of shredded metalfilaments for entrapment of grease and the like. The filter 37 is ofactivated charcoal which may be replaced or reactivated periodically.

In a preferred embodiment of the invention, the motor 31 is in the formof an uncased motor with a shroud. An open-ended cylindrical shroudencases the motor and assists in anchoring the motor in the drawer. Themotor is isolated from the principal flow of intake air by plates 50 and51. Plate 50 forms an inner wall for the chamber in which the fanelement 32 operates. Plate 51 forms an inner wall for the chamber inwhich the fan element 33 operates. The wall 50 is illustrated in FIGURE3 and is provided with an enlarged opening 52, coaxial with the shaft 53of the fan. The end of shroud 54, which encases the motor 31, is alsoseen in FIGURE 3. The end plate 51 is shown in FIGURE 4. The shaft 53extending from the motor 31 to the fan element 33 passes through arelatively small opening 55 in the plate 51. When the shaft 53 passesthrough the plate 50, the large opening 52 receives the end of shroud54. The shroud for the motor 33 in the region between the plates 50 and51 has an opening 56 therein. Thus, air will be drawn into the motorcompartment through the opening 56, will pass through the motor insidethe shroud 54, and will be drawn into the stream of air driven by thefan element 32. The air flow is thus given direction by reason of thelarge opening 52 in the plate 50, with the shroud 54 being spaced but aminimal distance from the periphery of the opening 52. At the other endwhere the shaft 53 passes through the small opening 55, air will have arelatively low impedance path for travel to the right end of the shroud54, through the motor 31, and into the chamber in which the fan element32 is housed. Air is permitted to enter the casing through the screenedopening 18 for passage through the motor 31. This serves to cool themotor and permit an extended operating life thereof.

The motor 31 is energized by way of a cable 60 which terminates in aplug 61. The plug 61 is a male plug which registers with a socket 62which is mounted on a removable bracket 63. A cord 64 extends from thesocket 62 to a male plug 65 which in turn cooperates with a convenienceoutlet in a supply box 66 which is located in a notch in the upper rearmargin of the casing 10. The junction box 66 is thus located outside thezone encompassed by the casing 10, but is within the perimeter of therectangular polyhedron outline of the casing 10. Power is fed to theplug 65 by way of a push-button switch which is actuated by the button67. Thus, when the drawer is closed, the rear surface 68 of the drawerengages the button 67 to remove power to the plug 65. The motor will beenergized by way of plug 65 any time the drawer 11 is opened. Closingthe drawer automatically de-energizes the motor.

In order to meet the Underwriters Laboratories requirements, and at thesame time permit the motor and fan unit 30 to be mounted in the drawer,provision has been made for completing the circuit from the supply box66 to the motor. More particularly, the drawer may be removed byactuating a stop or latch to permit the drawer to travel outwardlybeyond the normal operat ing position. When this is done, the outwardmovement of the drawer causes the cord 64 to become taut as to pull theplug 65 from its socket. Thus, the drawer can be removed and at the sametime the energizing circuit will be broken. When the drawer is to bereplaced, the plug 61 will be disengaged from the socket 62, the holder63 will be disconnected or unsnapped from its moorings in the wall 70 ofthe drawer 11. The plug 65 will then be inserted into its cooperatingsocket. The drawer may then be inserted and the holder 63 may then besnapped back into its position in the wall 70. The plug 61 may then beinserted into the receptacle 62 by access through opening 35 uponremoval of the filters 36 and 37.

FIGURE 6 illustrates an embodiment of the invention in which the motorunit 75 is mounted on the rear wall 76 of the casing 10. In thisembodiment, the drawer 11 is open at the rear and has only the twofilters, such as filters 36 and 37, mounted in the front opening in thebottom panel of the drawer 11. The filters are mounted as illustrated inFIGURES 2-5. In the embodiment of FIGURE 6, power is supplied from asupply junction box 77 with a push-button switch actuated by thepushbutton 78 when the drawer 11 is opened. The fan unit is providedwith three upwardly directed openings 80, 81 and 82. Openings and 82 areexhaust ports, and opening 81 is an intake port for air which will serveto cool the motor as above explained in connection with FIGURES l-S.However, in this case, provision is made externally of the casing 10 forcontrol of the inflow and outflow through the openings 80-82.

More particularly, the unit of FIGURE 6 is provided with a fitting 85for a vented hood application, and with fitting 86 if no external ventis to be employed. In this case, the filtered air is to be exhaustedback into the room in which the unit is installed.

When the unit is to be vented, the mixture 85 is mounted over theopenings 8082 by suitable screws engaging the flanges 87 and 88 tofasten the fixture 85 onto the top plate 15 of the casing 10. Thefixture 85 is adapted to be connected at its upper rim 90 to arectangular exhaust duct which may extend into an attic or to theoutside above the location of the hood. Thus, air passing through ports80 and 82 will flow upwardly through the ducts secured to the rim 90 andwill be exhausted. A damper 91 is provided to prevent inflow of airdownward from the outside into the hood. A central section 92 isseparated from the side portions in the fixture 85 and is open at thefront and rear so that air may flow downward into the port 80 forcooling the motor in the unit 75. The motor will be enshrouded and willbe ducted into the left and right hand portions of the unit 75 in themanner illustrated in FIGURES 2-4. Thus, air will flow into the port 80through the shroud over the motor and out through the fan driving airthrough the duct 80. The fixture 85 has downwardly depending flaps suchas the flap 93 which extends downwardly along the side walls of the port80. thereby to assist in controlling the flow of air downward into themotor.

When the unit is to be employed without an exterior duct, the fixture 86is substituted for the fixture 85. Fixture 86 has side panels 95 and 96,and a rear panel 97 with an inwardly depending lip 98. A front panel 99extends across the front edge of the fixture 86. The top panel 100extends from the rear panel 97 to an edge 101 which is spaced rearwardlyof the front panel 99. Thus, air may flow upward into the fixture 86from ports 80 and 82 and may flow outwardly from the zones 102 and 103to emerge from slots 104 and 105, respectively. The fixture 86 isprovided with a pair of narrow elongated bafile plates 106 and 107. Abottom plate 108 extends from the front portion 109 to the rear margin110. The plates 106 and 107 have downwardly depending lips 111 and 112.The lips 111 and 112 are adapted to extend downwardly and along the sidewalls of the port 81. The suction created in port 81 by the fan in unit75 draws air inward through slot 109 for travel downwardly through theopening 113 and thence into the motor in unit 75. The fixture 86 will beattached to the top of the casing with the opening 113 in registrationwith the duct 81.

Thus, in accordance with the invention, a casing forms a rectangularpolyhedron having a short wide front opening. A drawer is mounted in thecasing and is slidable through the opening with an intake port extendingacross the front half of the bottom drawer panel. The motor and fanmounted within the casing draw air into the drawer through the intakeport. Duct structure is provided for directing air flow from the fan outof the casing. In a ductless embodiment, the motor and fan are mountedin the drawer structure itself, with the output duct emerging throughthe front portion of the top drawer panel. In the ducted embodiment, themotor and fan are mounted at the rear of the casing. In either case, acontrolled how of air is maintained over the motor itself.

FIGURE 7 illustrates a modification of the invention in which the hoodof FIGURES 5 and 6 is installed above an oven 120. The construction issuch that the motor in the exhaust fan automatically is shielded fromexcess heat from the oven. The oven 120 is part of a unitary cookinginstallation in which surface cooking elements 121 and 122 arepositioned at counter level with the oven 120 being at eye level. Thehood 123 is vented and thus is of generally the same construction as thehood of FIGURES 5 and 6. It is provided with the roll-out constructionillustrated in FIGURE 6 and is fitted with the duct unit adapter 124which is like unit 85 of FIGURE 6. A rectangular vent pipe 125 extendsfrom adapter 124 to atmosphere behind the wall of a cabinet 126. Whenthe surface units 121 and 122 are to be employed, the hood 123 will beextended to exhaust the hot air and the fumes created by the cookingoperation on the surface cooking elements. However, when the oven 120 isoperated with the hood 123 retracted or closed, a flow channel isprovided for bypassing the exhaust hood 123. More particularly, a duct127 extends across the front of the oven 120 and serves as a flowchannel for hot air escaping from the oven through ports 128, asindicated by arrow 129. Hot air from the oven will then flow through thepassage 127 along the bottom of the hood 123 and then upward through thevertical riser 130 at the back of the hood 123. The air is then directedinto the vertical exhaust duct 125 at the juncture 131. The wall of thehood 123 is covered with an insulating layer 132 to protect the hood 123from high temperatures when the exhaust fan is not in operation.

The hood construction shown in FIGURE 7 shunts high temperature airalong the bottom of the hood and into the duct 125 above the outlet fromthe blower 133. As described in connection with the embodiment of FIG-URE 6, the fan motor is supplied with the cooling air system of FIGURE7, the flow of heated air from the over 120 through the juncture 131creates a low pressure within the hood 126 so that cool air will bedrawn through the cooling supply duct (duct 81, FIGURE 6) for flow overthe blower motor and then upward (through the ducts 80 and 82, FIGURE 6)to the exhaust duct 125. Thus, the blower motor will be shielded fromthe high temperatures ordinarily encounted when an exhaust hood isinstalled over an oven. The flow of cool air into the motor, under theforce produced by the flow of hot air into the upper reaches of theduct, will maintain the motor cool and thus leave it free from damageeven though it is located in close proximity to the oven 120. At thesame time, the motor stands ready to exhaust air from above the surfacecooking elements 121 and 122. The duct 127, the riser 130, and theadapter 134 leading to the juncture 131 preferably will all havecross-sectional areas adapted to promote flow through duct 127.

The duct 127 maybe made integral with the hood 123 or may comprise anadapter unit. In installations where the oven 120 is vented through thetop panel 135 rather than through front ports 128, the bottom panel 136of duct 127 will be perforated.

The unit of FIGURE 7 is particularly suitable for installation over aneye-level oven. The casing has a depth and a width approximatelycorresponding with the depth and width of the oven. A short, wideopening extends across the front of the casing to receive the filterdrawer which is slidable through the front opening. The motor and fan inthe casing may be used to draw air into the drawer through a filter in abottom opening. A first duct directs air flow from the fan toatmosphere. A secondary duct serves to direct air through and over themotor and into the stream of air driven by the fan. A third duct extendsalong the bottom of the casing and has a bottom inelt port. The thirdduct has an outlet which communicates with the first duct at a pointlocated downstream of the fan and the motor, so that heated air in theduct above the motor will produce low pressure in the casing when themotor is not in operation. As a result, outside air will flow over themotor to protect it from the heat of the oven.

Having described the invention in connection with certain specificembodiments thereof, it is to be understood that further modificationsmay now suggest themselves to those skilled in the art and it isintended to cover such modifications as fall within the scope of theappended claims.

What is claimed is:

1. A kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer slidable through said opening in said casing and having anintake port extending across the from half of a bottom panel,

(c) a motor and fan mounted in said drawer for drawing air into saiddrawer through said intake port,

(d) duct structure mounted within said drawer for directing air flowfrom said fan out of said casing.

(e) air filter means located between said port and said fan in the airpath, said (f) a secondary duct structure mounted in said drawer fordirecting air through said motor and into the air stream from said port.

2. The combination set forth in claim 1 in which said secondary ductstructure includes a cylindrical shroud around said motor which is flowconnected between the outside of said casing and a low pressure zone insaid casing created by said fan.

3. The combination set forth in claim 1 in which said motor is mountedin said drawer and sai dsecondary duct structure is supplied from asecondary port in the rear panel of said drawer and includes acylindrical shroud around said motor which is flow connected betweensaid secondary port and a low pressure zone in said drawer created bysaid fan.

4. A kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer having a top wall and slidable through said opening in saidcasing and having an intake port extending across the front half of thebottom panel,

(c) cooperating means on the casing and the drawer for supporting thedrawer on the casing and for permitting movement of the drawer throughthe from opening of the casing between a closed position wherein theintake port of the drawer is located within the casing and an openposition wherein the intake port is located without the casing,

[(c)] (d) a motor and fan mounted within said casing for drawing airinto said drawer through said intake p [(d)] (e) duct structure formedby a top panel of said casing and a fixture secured [over] to said toppanel and having an output port along'the top front margin of saidcasing for directing air flow from said fan out of said casing, and

[(e)] (f) air filter means mounted in the drawer and extending across[located between said intake port and said fan in the air path].

5. A ductless kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer slidable through said opening and having an intake portextending across the front half of a bottom panel,

(c) fan means mounted in said drawer adjacent to a rear panel thereoffor drawing air into said drawer through said intake port,

(d) duct structure in said drawer for directing air flow from said fanout of said drawer at the front half of a top panel, and

(e) air filter means located between said port and said fan in the airpath.

6. A ductless kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortWide front opening,

(b) a drawer slidable through said opening and having an intake portextending across the front haif of a bottom panel thereof,

(c) a motor and fan means mounted in said drawer adjacent to a rearpanel thereof for drawing air into said drawer through said intake Port,

((1) duct structure in said drawer for directing air fiow from said fanout of said drawer at the front half of a top panel,

(e) air filter means located between said port and said fan in the pathof air flow, and

(f) structure for directing air through said motor into said ductstructure.

7. A ductless kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer slidable through said opening in said casing and having anintake port extending across the front half of a bottom panel thereof,

(c) a central motor and two squirrel-cage fan elements mounted in saiddrawer adjacent to a rear panel thereof for drawing air into said drawerthrough said intake port,

(d) duct structure in said drawer including chambers for said elementsopen at opposite ends and an output channel for directing air flow fromsaid fan out of said drawer at the front half of a top panel,

(e) air filter means located between said port and said fan in the pathof air flow, and

(f) structure for preferentially directing air through said motor intoone of said chambers.

8. In a ductless kitchen filter, the combination which comprises:

(a) a rectangular polyhedron casing having top, bottom, and end panels,a short wide rear panel and a short wide front opening,

(b) a drawer slidable into said front opening and having closed frontand end panels, a perforated rear panel, a bottom panel open across thefront half to form an air inlet port, and a top panel having ductstructure opening through the front half thereof forming an outlet port,and

(c) means including a motor and fan mounted in said drawer for movingair from said inlet port to said outlet port.

9. The combination set forth in claim 8 in which:

(a) an electric supply unit is mounted at the rear of said casing,

(b) a flexible linkage extends from said supply unit into said drawerand is connected to said motor, and

(c) a switch means on said supply unit in circuit with said motor whichis actuated by contact with the rear panel of said drawer totie-energize said motor.

10. The combination set forth in claim 8 in which an electric supplyunit for said motor is mounted at the rear of said casing with a powercircuit extending from said unit to said motor including an intermediateconnection accessible through said inlet port and a second connection atsaid supply unit which is broken when said drawer is removed from saidcasing.

11. In a ductless kitchen filter, the combination which comprises:

(a) a rectangular polyhedron casing having top, bottom, and end panels,a short wide rear panel and a short wide front opening,

(b) a drawer having a closed front panel, closed end panels having topand bottom marginal grooves, a perforated rear panel, a bottom panelopen across the front half to form an air inlet port, and a top panelhaving duct structure opening through the front half thereof forming anoutlet port,

(c) a pair of rollers spaced along the and panels of said casingengaging each said marginal groove for slide movement of said drawerinto and out of said casing, and

(d) means including a motor and fan mounted in said drawer for movingair from said inlet port to said outlet port.

12. The combination set forth in claim 11 in which a unitary platesupports two pairs of said rollers adjacent to each end of said casingwith each said plate being anchored to the top and bottom panels of saidcasing.

13. A kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer having a top wall and slidable through said opening andhaving an intake port extending across the front half of a bottom panel,

(c) fan means mounted within said casing adjacent to a rear panel fordrawing air into said drawer through said intake port,

(d) duct srtucture in said [drawer] casing for directing air flow fromsaid fan out of said casing, and

(e) air filter means mounted in said drawer in a plane parallel to saidintake port and in the air path leading to said fan.

14. A kitchen filter which comprises:

(a) a casing having the form of a rectangular polyhedron with a shortwide front opening,

(b) a drawer slidable through said opening in said casing and having anintake port extending across the front half of a bottom panel,

(0) a motor and fan mounted within said casing for drawing air into saiddrawer through said intake port,

(d) a first duct structure for directing air flow from said fan toatmosphere above said casing,

(e) air filter means located between said port and said fan in the airpath,

(f) a second duct structure for directing air through said motor andinto the air stream from said port, and

(g) a third duct structure extending along the bottom of said casinghaving a bottom port and communicating with said first duct structure ata point located downstream of said fan and said motor.

15. A kitchen exhaust unit for installation over an eyelevel oven whichcomprises:

(a) a casing having depth and width corresponding with the depth andwidth of said oven and having a short wide front opening,

(b) a drawer slidable through said opening having an intake porttherein,

(c) a motor and fan mounted within said casing for drawing air throughsaid drawer,

(d) a first duct structure for directing flow of air from said fan andout of said casing,

to) filter means mounted in said drawer in the path of air moved by saidfan,

(f) a secondary duct structure for drawing air from outside said casingthrough and over said motor and into the airstream driven by said fan,and

(g) a third duct structure extending along the bottom of said casing andhaving a bottom inlet port, said third duct structure having an outletport communieating with said first duct structure at a point locateddownstream of said fan and said motor.

16. The combination set forth in claim 15 in which ing and having anintake port extending across the from half of the bottom panel thereof,

(0) a motor and fan mounted in said drawer for drawing air into saiddrawer through said intake port,

(d) duct structure mounted within said drawer for directing air flow toand from said fan and out of said drawer,

(e) air filter means located between said port and said fan in the airpath,

(f) an electrical supply box mounted in said notch within saidrectangular polyhedron form,

(g) a removable electrical circuit extending from said box to saidmotor, and

(h) switch means within said casing positioned in the said bottom inletport in said third duct extends along 10 the top front margin of saidoven.

17. The combination set forth in claim in which said third ductstructure has an insulating wall separating it from the zone in saidcasing occupied by said drawer,

motor and fan. 15 path of movement of said drawer and operable in 18. Ina kitchen filter, the combination which comdependence upon opening ofsaid drawer to supply prises: power to said motor and fan.

(a) a casing having the form of a notched rectangular polyhedron with ashort wide front opening,

(b) a drawer mechanism slidable through said opening in said casing andhaving an intake port extending References Cited The followingreferences, cited by the Examiner, are of record in the patented file ofthis patent or the original across the front half of a bottom panelthereof, patent,

(c) a motor and fan mounted within said drawer for UNITED STATES PATENTSdrawing air into said drawer through said intake 2 828 683 4/1958 Josephat a 98 5 K opening, I i

(d) duct structure mounted within said drawer for digi at 2 recting airHow to and from said fan and out of said 3026788 3/1962 gi 98 1l 5 Kdrawer,

(e) air filter means located between said port and said $223 33 g E fanin the air path,

(f) an electrical supply box positioned within the outzzg K line of saidrectangular polyhedron and shielded 3249'037 5/1966 K from air flowingfrom said intake port through said 32s1540 5/1966 Ki n & E duct,

(g) removable electrical connection extending from 35 g2 K i said and 3364 664 1/1968 Desi? e a 98115 E (h) switch means within said casingpositioned in the path of movement of said drawer and operable inFOREIGN ATENTS dependence upon opening of said drawer to supply 888,8232/1962 Great Britain 98-115 K power to said motor and fan. 40

19. A kitchen filter which comprises:

(a) a casing of rectangular polyhedron form with a short wide frontopening and an inwardly depending notch in a rear portion thereof,

(b) a drawer slidable through said opening in said cas- FRANK W. LUTTER,Primary Examiner B. NOZICK, Assistant Examiner us. 01. X.R. se 11s K [223? UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTIQN Patent Re-27.225 Dat November 9. 1971 Invent -GU. E. STALKER It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

r- Column 1, line 32 "filtartion" should be fi1tration--;

Column 5, line 52 after "air" add which enters by way of the channel 81,FIGURE 6. In the- Column 5, line 54 "over" should be oven-; Column 6line 13 "inelc should be "inlet"; Column 6 line 49 "sai dsec'ondary"should be said secondary- Column 9, line 35 "connection" should be-conne ctions- Signed and sealed this 25th day or July 1972.

' (SEAL) ut-ttest:

EDWARD M.FLETCHER,JR. ROBERT GOTJTSCHALK Attesting Officer Commissionerof Patents

